<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    * {
      margin: 0;
      padding: 0;
    }

    body {
      display: flex;
      justify-content: center;
      align-items: center;
      height: 100vh;
    }

    a {
      position: relative;
      text-decoration: none;
      overflow: hidden;
      background: linear-gradient(90deg, blue, #5d5de9);
      color: white;
      padding: 10px 20px;
      border-radius: 40px;
      letter-spacing: 2px;
    }

    span {
      position: absolute;
      background: #ffffff;
      transform: translate(-50%, -50%);
      animation: move 1s linear infinite;
      border-radius: 50%;
      pointer-events: none;
    }

    @keyframes move {
      from {
        width: 0px;
        height: 0px;
        opacity: 0.7;
      }

      to {
        width: 500px;
        height: 500px;
        opacity: 0;
      }
    }
  </style>
</head>

<body>
  <a href="#">JavaScript</a>
  <script>
    let a = document.querySelector('a');
    a.addEventListener('click', function (e) {
      let span = document.createElement('span');
      span.style.left = e.offsetX + 'px';
      span.style.top = e.offsetY + 'px';
      this.appendChild(span);
      setTimeout(() => {
        this.removeChild(span);
      }, 1000);
    })
  </script>
</body>

</html>